This invention relates to aircraft distance measuring equipment (DME), and more particularly to improvements in digital DME systems.
Conventionally, DME operation involves the transmission of a radio signal of specified character from an aircraft to a ground station. After specified delays and under known constraints at the ground station, a reply signal is radioed back to the aircraft. Once the return signal is identified, and known time delays are accounted for, the duration between transmission and reception is decoded to yield distance from the ground station to the aircraft.
It is a primary object of the present invention to provide a representation of aircraft velocity utilizing signals which are available in DME systems.